Visible transmittance (VT) is the measure of light going through a window. Glass coating, tints, grids and muntins affect VT as they block some light. Renewal by Andersen® of Arkansas talks about other factors that affect VT.
Double or Triple Pane Windows
Fewer panes result in higher VT since light will pass through the layers of glass. Double pane windows have a VT rating of 0.54 to 0.56. A triple pane window of good quality will have a VT of 0.42 or better. Some will go as low as 0.30 depending on the window and the glass option. A lower VT means a darker room, so you need to understand what you’re selecting.
VT or Efficiency
A more efficient window can sometimes result in a lower VT. That’s a tradeoff you’ll need to consider. If you want to let more sunlight in, look for the higher VT option. Otherwise, go for the more efficient option with a lower VT. It all depends on your preference as a homeowner. VT should not be too low for it can defeat the purpose of the window, which is to see what’s outside, admit light inside and avoid using electric lights in the daytime. Seek the advice of a trusted window replacement contractor like Renewal by Andersen of Arkansas to help you determine what will work best for you.
If the window is well-shaded, keep VT high to keep the window from appearing dark and to allow more daylight inside. VT of 0.75 is high enough. To keep the VT from going too low, use operable interior shades. They can be very effective for glare mitigation, and you’ll get a higher VT. Such shades should have bright, reflective surfaces facing the window.
From bay windows to picture windows, Renewal by Andersen of Arkansas is the replacement window company for all your needs. Call us at (479) 250-3588 for a free estimate. We are here to serve you in Fayetteville, AR, and other nearby areas.